Deep venous thrombosis in pregnant women

The main risk factors for deep vein thrombosis in pregnancy and after delivery are preeclampsia, operative delivery, adiposity, prolonged bed rest, and haemostatic defects (antithrombin, protein C and protein S deficiencies), activated protein C resistance, lupus anticoagulant/antiphospholipid antibodies. Hyperhomocystinaemia is a general risk factor for deep vein thrombosis. The clinical diagnosis of deep vein thrombosis is difficult and must be confirmed by imaging techniques. Positive D-dimer has high sensitivity, but low specificity to detect acute thrombosis. Standard treatment is unfractionated heparin intravenously for 7-10 days, followed by subcutaneous injections. Anticoagulant treatment is prolonged for 6-12 weeks after delivery, usually with warfarin. During pregnancies associated with high risk of thrombosis, low molecular heparin prophylaxis is given during pregnancy and 6-12 weeks after delivery. Thrombosis in pregnancy must be followed by adequate investigation for an underlying thrombotic predisposition.     

Deep venous thrombosis in a patient with superficial thrombophlebitis. Apropos of 2 cases]

Many schools refer children who have sustained an injury, directly to the local Accident & Emergency (A&E) department. This prospective study monitored these referrals for one school term (08.01.96-31.03.96). During this time 200 children under the age of 14 years presented from school to the A&E department of the Royal Aberdeen Childrens Hospital (RACH). The majority presented with trivial or mild injuries and 45% of parents felt that attending A&E was inappropriate. Half the accidents happened to unsupervised children. Rural children and children of working parents were less likely to attend A&E. In Grampian Region school referrals to A&E generate a significant workload for the A&E department with resultant cost implications. It would appear that a large number of these attendances are medically unnecessary and result from a desire by the school to avoid any complaint or litigation.     

Deep venous thrombosis: prediction by D-dimer?

The utility of D-dimer as an inexpensive, noninvasive method of diagnosing deep venous thrombosis (DVT) is debated. We sought to determine whether a qualitative D-dimer assay would have a high correlation with DVT in 65 hospitalized patients who were randomly referred for diagnosis of DVT by venous duplex and duplex Doppler ultrasonography. Patients were excluded from the study if they had any inflammatory, infectious, or malignant condition associated with elevation of D-dimer. The mean level of D-dimer in patients with DVT (16 of 65 patients) was 5,141 ng/mL, compared with 3,024 ng/mL in those without DVT, but there was considerable overlap between the two groups. No patients with a D-dimer level < 2,000 ng/mL had DVT. We conclude that the qualitative D-dimer assay is an excellent exclusionary test for DVT at levels less than 2,000 ng/mL. Limitations of the D-dimer assay and cost-effective issues are discussed.     

Deep venous thrombosis and neoplastic pathology: our experience in emergencies

Deep vein thrombosis incidence is 1/1000 per year; it is associated with many risk factors which is considered as "thrombophilic states". Its pathogenesis is complex, caused by alterations of hemostasis system. Many studies have established the relation between cancer and subsequent venous thromboembolism, confirming the relationship of neoplastic cell interaction with coagulation system. Forty-seven patients admitted to the hospital from 1987 to 1996 with symptomatic clinically proved deep vein thrombosis were included in a retrospective study. Routine examination at the time of diagnosis of deep vein thrombosis revealed an occult cancer in 8 out of 47 patients; 9 out of 47 patients were admitted in hospital with vein thrombosis and known cancer. The aim of this study is to suggest the best, first treatment of vein thromboembolism in emergency to avoid the dangerous pulmonary embolism complication. The patients affected with deep vein thrombosis and cancer were elderly (over 70 years old, in mean); the neoplasia was of digestive system (8/17) in advanced metastatic stage there was cancer familiarity in 7 out of 47 patients. The high risk of pulmonary embolism associated to deep vein thrombosis suggests the importance of early starting the anticoagulant therapy and placing caval filter.     

Deep venous thrombosis: epidemiologic, diagnostic and therapeutic aspects

Deep vein thrombosis (DVT) has a high social and economic cost disease being its prevalence in the general population elevated and producing possibly fatal (pulmonary embolism) or disabling (post-thrombotic syndrome) complications. Thus, it appears of great importance to know the epidemiological and clinical characteristics of DVT in order to perform the best diagnosis, therapy and prophylaxis. The study population is composed by 146 patients (84 males and 62 females, mean age 60.9 +/- 15.3 years, range 19.92 years), arrived in our Vascular Echography Laboratory with the clinical suspect of DVT confirmed by means of echo color Doppler. The most frequent clinical signs were skin hyperthermia in 118 patients (80.8%) and edema in 116 patients (79.5%), while the most common symptom was pain, 89 patients (61.0%). Eleven patients (7.5%) were asymptomatic. The echo criteria utilized were direct thrombus visualization, vessel diameter higher than the contralateral, reduced or absent vessel wall ability to be compressed, reduced or absent color Doppler venous flow, lack or reduction of respiratory flow modulation, visualization of collateral circulation. DVT was located in 131 patients (89.7%) in inferior limbs (proximal in 122 patients, isolated distal in 9 patients), in 14 patients (9.6%) in superior limbs and in 3 patients (2.1%) in the internal jugular vein. In 130 patients a risk factor or a predisposing condition was identified: secondary DVT; in 16 patients the DVT was considered idiopathic. The most frequent risk factors were: previous surgery 28.1%, immobilization 19.9% trauma 17.1%, tumors 9.6%. A hypercoagulation was detected in 4 patients: antithrombin III deficit in 2, post-splenectomy thrombocytosis in 1 and antiphospholipid antibodies syndrome in the last one. The Pisa territory epidemiologic data showed a male 0.51 and female 0.38/1000 subject/year DVT incidence, with significantly higher values in older than 45-54 males and 55-64 females. One hundred and thirty one patients were treated with 5-11 day heparin infusion and thereafter with warfarin at least for 6 months, 1 year or indefinitely depending on thromboembolic risk. Six patients with distal DVT and 9 patients with hemorrhagic risk were treated with subcutaneous calcic or low weight heparin. In 1 patient with a mobile thrombus judged as at very high risk of embolization, a caval filter was positioned. Anticoagulant therapy complications were: 2 minor bleedings, 1 alopecia, 1 thrombocytopenia. Two patients died for neoplastic complications. Fifty-seven patients completed a 6-month follow-up and were submitted to a control each study that evidenced: total recanalization in 15 (26.3%), partial recanalization in 25 (43.9%) and no recanalization in 17 patients (29.8%). In 6 patients there was a DVT relapse and in 9 pulmonary embolization: almost all these patients were in the partial recanalization group.     

Deep venous thrombosis complicating a congenital absence of the inferior vena cava

BACKGROUND AND PURPOSE: The use of left ventricular assist devices has become an established method in bridging patients with end-stage cardiac failure to heart transplantation. Since thromboembolism is one of the major complications, we undertook this study to evaluate the clinical significance of Doppler microembolic signals (MES) in patients with left ventricular assist devices. METHODS: Six patients with left ventricular assist devices were monitored for MES with transcranial Doppler ultrasonography during the first 30 postoperative days. Additionally, repeated (10 per day and patient) and prolonged (3 hours per patient) monitorings were performed to assess the adequacy of the 30-minute recordings. Three observers evaluated 30 randomly assigned monitorings in a blinded fashion to assess the interobserver variability. The relation between MES counts and clinical, radiological, hemostaseological, and pump flow parameters and the predictive value of MES counts regarding the occurrence of embolic events was evaluated. RESULTS: Ten ischemic cerebrovascular accidents and 2 peripheral thromboembolic events occurred during the observation period of 177 days (total incidence, 6.8%). MES were found in 143 of 170 monitorings (84.1%). Their counts were significantly higher on days with clinically manifest embolic events as compared with event-free days (18.5 [3-74] versus 4 [0-52], respectively, median and 95% CI; P < .001, Mann-Whitney). The predictive value of MES counts above 7 per 30 minutes was high (75%). Significant differences in the incidence and counts of MES as well as in the incidence of clinically manifest embolic events were noted among the six patients (all P < .01) without equal differences in anticoagulant treatment or pump flow. Interobserver agreement was high (p = .78 to .89, unpaired Student's t test). Considerable short- and long-term intrapatient variations of MES counts, without consistent pattern, were noted. CONCLUSIONS: Serial monitoring for MES is prognostically superior to single monitorings in patients with left ventricular assist devices. In the future, this new application mode may individually guide anticoagulation strategies and even influence the decision regarding early cardiac transplantation versus long-term use of the assist devices.     

Foot pump prophylaxis for deep venous thrombosis: the rate of effective usage in trauma patients

Only nine cases of primary multifocal leptomeningeal gliomatosis (PMLG) have been reported. We describe the first child with malignant features of PMLG who was diagnosed during life. The differential diagnosis based on imaging findings includes infectious and lymphoproliferative disorders.     

Deep venous thrombosis: incidence on admission to a brain injury rehabilitation program

OBJECTIVE: To determine the incidence of deep venous thrombosis (DVT) in brain injured individuals at time of admission to a brain injury (BI) rehabilitation program. DESIGN: Prospective study, sequential case series. SETTING: University tertiary care BI rehabilitation center. DATA SET: Eighty-two traumatic brain injury (TBI) and 71 atraumatic brain injury (ABI) patients were consecutively admitted to our BI unit over a 12-month period and screened within 24 hours of admission for a lower extremity DVT with color flow duplex Doppler ultrasonography. All patients had been prophylaxed with either subcutaneous heparin anticoagulation therapy or intermittent compression devices, and all patients were within 2 months of the original BI. MAIN OUTCOME MEASURES: Evidence of intrinsic venous occlusion by duplex Doppler. RESULTS: DVTs were detected and treated prior to rehabilitation admission in three patients (2%), and these persisted at rehabilitation admission. New DVTs were detected at time of rehabilitation admission in 17 patients (11%). All were occult DVTs; none of the 17 patients had clinical findings indicative of acute DVT. No significant differences were noted in the TBI group when age, highest 24-hour Glasgow Coma Scale score, length of acute hospitalization, type of DVT prophylaxis, or presence of an extremity fracture were compared for individuals with and without DVT. No significant differences were noted in the ABI group when age, length of acute hospitalization, and type of DVT prophylaxis were compared for individuals with and without DVT. CONCLUSION: The overall incidence of DVTs was 13% and the incidence of occult DVT was 11%. Individuals with TBI had an overall incidence of DVTs of 20% and an occult DVT incidence of 18%. Individuals with ABI had an overall incidence of DVT's of 6% and an occult DVT incidence of 4%. These findings indicate the importance of baseline screening for DVT in this patient population.     

Cost-effectiveness of enoxaparin versus low-dose heparin for prophylaxis against venous thrombosis after major trauma

We attempted to determine health and economic outcomes from the perspective of an integrated health system of administering enoxaparin 30 mg twice/day versus heparin 5000 U twice/day for prophylaxis against venous thrombosis after major trauma. A decision-analytic model was developed from best literature evidence, institutional data, and expert opinion. We assumed that 40% of proximal deep vein thromboses (DVTs) and 5% of distal DVTs are diagnosed and confirmed with initial or repeat duplex scanning; 50% of undiagnosed proximal DVTs result in pulmonary embolism; 2% and 1% of undiagnosed proximal DVTs will lead to readmission for DVT and pulmonary embolism, respectively, and pulmonary embolism-related mortality rates range from 8-30%. Length of hospital stay data and 1996 institutional drug use and acquisition cost data were used to estimate the cost of enoxaparin and heparin therapy. Diagnosis and treatment costs for DVT and pulmonary embolism were derived from institutional charge data using cost:charge ratios. A second analysis of patients with lower extremity fractures was completed. One-way and multiway sensitivity analyses were performed. For 1000 mixed trauma patients receiving enoxaparin versus heparin, our model showed that 62.2 (95% CI -113 to -12) DVTs or pulmonary emboli would be avoided, resulting in 67.6 (8 to 130) life-years saved at a net cost increase of $104,764 (-$329,300 to $159,600). Enoxaparin versus heparin resulted in a cost of $1684 (-$3600 to $9800) for each DVT or pulmonary embolus avoided and a discounted cost/life-year saved of $2303 (-$8100 to $19,000). For 1000 patients with lower extremity fractures, enoxaparin versus heparin resulted in a cost of $751 (-$4200 to $3300) for each DVT or pulmonary embolus avoided and a discounted cost/life-year saved of $1017 (-$10,200 to $6300). Although enoxaparin increases overall health care costs, it is associated with a cost/additional life-year saved of only $2300, which is generally lower than the commonly used hurdle rate of $30,000/life-year saved. The cost-effectiveness ratio is more favorable in patients with lower extremity fractures than in the general mixed trauma population.     

Anticoagulants for venous thrombosis

The anticoagulant agents heparin and warfarin were introduced before the era of randomised clinical trials. As a result, the indications, dosages and monitoring techniques of these drugs have undergone re-evaluation in multiple clinical trials in the past years. Low molecular weight heparin has been developed, which has led to new approaches in anticoagulant management. Current levels of laboratory, pharmacology and clinical knowledge in the treatment of venous thromboembolism are discussed.